Improvement in thread-cutters for sewing-machines



UNITED STATES PATENT OFFICE.

FRANCIS V. OBURG, OFPEORIA, ILLINOIS.

IMPROVEMENT IN THREAD-CUTTERS FOR SEWING-MACHINES.

Specification forming part of Letters Patent No. 13?,947, dated April 15, 1873; application filed January 11, 1873.

To all whom it may concern:

Be it known that I, FRANCIS V. ()BURG, of

Peoria, in the county of Peoria and State of 2, 3, and 4 are views of my blade.

This invention has relation to thread-cutters for sewing-machines and it consists in the means by which the knife is seated firmly in the lower part of the front plate of the machine without pivot, screw, or rivet so that it can be readily removed for sharpening or renewal.

The frequent necessity for cutting the threads in operating with a sewing-machine renders some device more at hand than a pair of scissors desirable. Many thread-cutters have been devised for this purpose, which have been in some cases complicated, and in others difficult of attachment. The object of the present invention is to provide a simple steel cutter which, by a little adaptation of the front plate, can be attached to its lower portion in such a manner that it will be perfectly secure and firm, and can at the same time be readily removed when necessary.

In casting the front plates core-spaces are usually formed, to lessen. the weight, as at a, in the plate A shown on the drawing. In this case it is only necessary to file the taperin g channel b through the wall in the rear face of the plate for the reception of the tapering shaft of the knife. If in an old machine there is no such core-space in the front plate,

a recess should be made to receive the knife.

In new machines the core-space can be properly placed for its reception. The knife B is formed of a simple steel plate, which may be about one-sixteenth of an inch in thickness.

The upper part of the plate is fashioned into a tapering shank, 0. The rear edge of the shank, which continues down to the heel of the blade, is arranged to fit the wall of the core-space. The front edge is inclined down= ward and toward the rear edge, terminating at the rear end of the cutting-edge. The blade 0 is formed at the lower end of the plate. The lower edge d of the plate extend ing from the rear edge of the shank forward,- is broad and somewhat curved upward to= ward the point of the blade. From this edge 61 the blade is beveled upward to the oblique cutting-edge e, which extends from said point upward and backward to the front edge of the shank. The general shape of the knife has a resemblance to a boot or a hook, the cutting-edge being the upper or inside edge of the hook end.

Having been properly finished, polished, and sharpened, the knife is ready for use upon being seatedin the tapering channel b through the wall of the front plate, the size and taper of said channel being made to correspond as exactly as possible with the size and taper of the lower or narrower part of the shank. In this manner the knife is readily made socure for use. work is held in one hand and the thread in the other. The thread, being placed upon the upper or cutting edge of the hook, is drawn toward the operator. The position of the knife is therefore extremely convenient,

and it is without danger, as the broad back of the blade is turned toward the operator and downward.

What I claim as my invention, and desire to secure by Letters Patent, is-

The front plate having the corespace a, with a downwardly-tapering channel, in combination with the knife B, having a downwardly-tapering shank, c, as specified.

In testimony that I claim the aboveI have hereunto subscribed my name in the presence of two witnesses.

FRANCIS V. OBURG.

Witnesses:

GEORGE W. GABLE, BARRETT WHITE.

In cutting the thread, the 

